Here is my exegesis and application of Malachi 3:13-4:3. If you would like to read this passage, which I recommend, you can go here.
Unquestionably, if the hope of reward is taken away and extinguished, alacrity [enthusiasm, willingness] in running will not merely grow cold, but will altogether be destroy. John Calvin
One of the most discouraging things in life is when your work bears no fruit. You go out and plant, water, and weed then a worm devours your plants. You work hard at your job putting in extra hours, trying to get the promotion and it does not come. You work fixing up your basement only to have the water heater break and flood the new carpet. The Christian life can feel much the same way. We sacrifice our money, our time, our energy and in some cases our dreams to follow our Lord and the payback can seem meager. If we assume our labor will not bear fruit we will lose heart and become lazy in our work. However, the Bible is clear that all labor done in the Lord will eventually be harvested. We see this explicitly in these New Testament verses:
I Corinthians 15:58 Therefore, my beloved brethren, be steadfast, immovable, always abounding in the work of the Lord, knowing that your labor is not in vain in the Lord.
Galatians 6:9 And let us not grow weary while doing good, for in due season we shall reap if we do not lose heart.
II Timothy 4:8 Finally, there is laid up for me the crown of righteousness, which the Lord, the righteous Judge, will give to me on that Day, and not to me only but also to all who have loved His appearing.
As we come to the end of Malachi we see that fellow saints in the Old Testament also feared that their labor might be in vain. They felt that it had been useless to serve the Lord. Like their New Testaments counterparts, God gives them reassurance that he has not forgotten them or their deeds. Those who fear God and obey his commands will be rewarded.
Malachi 3:13-4:3 is the sixth and final disputation in Malachi. There are several key differences between this disputation and the previous ones. First, God debates not with the wicked, but rather with the righteous. These people in this section are described as those who have “kept His ordinance and walked as mourners.” (vs. 14) The phrase “kept his ordinance” can mean generally obeying the commands of God or it can refer to priestly duties. It is possible these are priests whose lives are very hard because no tithe is being brought into the house of God. (c.f. 3:8-9) These priests mourn over the sin in the land and exaltation of the proud. These priests have honored God with their actions but are now dishonoring him with their words. They speak harshly against God. Their service to him is unprofitable while the proud and wicked are blessed and raised up. Those who test God go free without feeling the divine wrath that they deserve. (vs. 15) This is similar to what we saw in 2:17.
The second key difference in this passage is that for the first time in Malachi we see the people accept the rebuke and change. Verses 13-15 are a rebuke from God. God is telling the priests that their words have been out of line. The priests listen and turn from their wicked ways. Those who fear the Lord get together and talk with one another. (vs. 16) It would appear that these men encouraged one another to remain faithful to God. While the exact words of the discussion are not recorded, Malachi does give us the result. The result is that God hears, writes their names in a book of remembrance, promises to spare them, to be their father, and to come in judgment against the wicked. (vss. 17-18)
Malachi then gives a more precise picture of this Day of Judgment. On this day the wicked will be completely burned up like stubble. (4:1) Note the similar phrasing to 3:15 where words “wicked” and “proud” are also used. God is reminding the priests that even though the unrighteous appear to go free and be blessed, their end is destruction. (See Psalm 73:17-20) The fire of God’s presence, which burns up the wicked, will be a Sun of Righteousness for those who fear the name of the Lord. (4:2) God will heal his people and make them fat like cattle that have no want. Finally, on this day God’s people will trample under the wicked. (4:3) It is an explicit teaching of both the Old and New Testaments that God’s people participate in the judgment of the wicked. (c.f. Micah 5:5-6 and Revelation 2:26)
Those who are serving God faithfully are tempted to become discouraged when their service does not immediately profit them. God tells us in both the Old and New Testaments that our service to Him is not in vain. (I Cor. 15:58) However, we often think that God must fulfill his promises immediately. We must be careful, as we faithfully serve the Lord, not to grumble when God’s promises are delayed. Let us work to please God and let him reward us as he wishes and when he wishes. The harvest is as sure as our God’s promises.
It is a great comfort and encouragement to have other Christians challenge us to turn back to God. We are not sure what was said in Malachi 3:16, but somehow the godly encouraged one another to remain faithful to the Lord and rebuked one another for their lack of faith. It is not enough just to be around each other. We must use our words to spur one another on to righteousness. (Hebrews 10:25)
We must remember that the difference between the righteous and the wicked is not always seen in this life, but will be clearly seen at the final judgment. (3:18-4:1-3) As we go through life, we should keep before our eyes the judgment day. This keeps us from losing heart and growing slack in our labor for God. We can say, “In this life I have trouble and tribulation as I strive to obey God. But in the next I shall be rewarded, while the wicked shall be paid back for all eternity.”
To love God is to fear God. Three times in this passage the priests are described as those who fear God. (3:16 twice, and 4:2) The fear of the Lord is not a popular subject in the modern church. But here those who fear God get a wonderful blessing; their names are written in the book of remembrance. Joyce Baldwin says, “The thought is that not one believer will be forgotten by God.” God knows those who fear him and belong to him. He is our Father and our names are stamped upon the pages of God’s book, from which they can never be erased. Let us have courage, grace and strength to be faithful to the Lord. “Let us not grow weary,” Malachi says, “For our names are written by God in his book. Therefore our reward is sure.”